Roasting-furnace.



PATENTED APR. 25, 1905.

P. J. FALDING.

R0 ASTING FURNAGE.

APPLIOATION HLBD MAR. 5, 1904.

2 SHEETS-SHEET 1,

Smog/mko@ No. 788,098. PATENTED APR. 25, 1905. P. J. FALDING.

ROASTING FURNACE.

APPLIOATION FILED MAB. 5, 1904.

A 2 SHEETS-SHEET z, Z.

UNITED STATES Patented April 25, 1905.

ATENT FFICE.

ROASTlNG-FURNACE.

SPECIFICATION forming part of Letters Patent No. 788,098, dated April25, 1905.

Application filed March 5,1904. Serial No. 196,695.

To r/J/ /r/mnt it '1m/y concern:

Be it known that I, Femenino J. FALnINe, a subject of the King' ofGreatBritain and lreland, residing' at New York, county of New York, andState of New York, have invented certain new and useful Improvements inRoasting'- Furnaces, fully described and represented in the following;specification and the accompanying' drawings, forming' a partof thesame.

This invention relates to improvements in roasting'- furnaces, andparticularly to that type of roasting-furnaces in which there are aseries of superimposed hearths and which employ a series of rotating'stirring-arms arranged above the hearths andcarried by a central shaft.

An object of this invention is to provide means for cooling' the shaftand the stirring'- arms, so that the deterioration of the stirring'-arms and that portion of the shaft to which they are secured, caused bythe intense heat necessary in the operation ofI the furnace, may bereduced to a minimum.

It is a further object of the invention to provide means for securing'the stirring-arms to the shaft, so that in case of any deteriorationthey may be drawn from the furnace and another arm inserted more quicklythan has` heretofore been possible and without necessitating' thecooling' down of the furnace. such cooling' being' a slow and expensiveoperation.

lt isa further object of the invention to provide means for securing'the stirring-arms to the shaft, by which the necessity of removing' thecentral shaft from the furnace, owing' to the unavoidable deteriorationof that portion of the shaft which carries the arms, is largely doneaway with.

A Vfurther object of the invention is to provide an improved stirring'arm which shall be stronger and more thoroughly cooled than armsheretofore employed.

Fora better understanding' of the invention reference will now be had tothe accompanying' drawings, in which Fig-ure I is a vertical section ofa furnace embodying' the invention in a preferred form. Fig'. 2 is across-section, on a larg'er scale, showing' the means employed forcooling' the arms and the shaft and for securing' the arms on the shaft.Fig'. 3 is a view on line 3 3 of Fig'. 2, partly in section. Fig'. i isa section on line t t of Fig'. i2. Figs. and 6 are sections taken onlines 5 and G 6 of Fig'. 2, showing' details of the improved stirring'-arms. Fig'. T is a view similar to Fig'. 2, but on the scale ofFig'. I,showing' a mo lilied construction embodying' certain features of theinvention.

Referring' now to the drawings illustrating' one embodiment of theinvention, A represents a furnace of the type heretofore mentioned,comprising' a cylindrical shell or casing' formed of a lire-brick wallB, inclosed by a steel shell C. Within the shell are arranged a seriesof superimposed hearths E and E, the hearths E having` central openingse0 to enable the ore or other material to be fed onto the hearths IC',the latter having' openings at their outer edge, as at Il, to enable theore to be fed to the hearths E. These hearths E and E are arrangedalternately above each other, as shown in Fig'. l, and have concentriccentral openings through which a shaft D is passed. This shaft l), whichcarries the stirring-arms F, is preferably of the downwardlytapering'form now used in this type of furnace and is revolubly mounted in ahollow standard I. The shaft is fitted to thchearths by being' providedwith downwardly-extendingl liang'es 4Q, adapted to eng'ag'eupwardlyextending' liang'es '-IB, provided on the hearths E'. By thismeans the shaft is secu rely mounted and at the same time left free torotate. The roof H o'f the furnace, which is preferably of cast metal,is provided with a feedopening' and another opening, 45, preferably atthe other side of the furnace for the escape of the products ofcombustion, which pass out through the stand-pipe 11. A 'furtheropeningl is provided in the center of the roof, concentric with theopenings of the hearths, through which the shaft is passed. The roofabout this opening' is provided with a liang'e 43, similar to theflanges carried by the hcarths IC', hereinbefore described, and theshaft is provided with the downwardlyextending' flang'e 4t2, whereby theshaft is snugly fitted and at the same time allowed to rotate in theopening'. Any suitable means for rotatingthe shaft maybe provided.Preferably, however, and as shown a circular plate 2 is secured to theshaft below the lowest hearth. This plate 2 is provided on its underface with a circular rack or gear which is adapted to engage with apinion 3 on the shaft 4, driven by any suitable power means.

Any desired means for feeding the ore or other material to the furnacemay be employed. As shown, however, and preferably there is provided ahopper 5, arranged on the top of the furnace, which is provided with thescrew-feed 6 on the shaft 7, driven by the same power means whichoperates the shaft 4 through the sprocket-wheels 8 and 8 and the chain9. A valve 10 may be provided to regulate the feed of the ore or othermaterial and is operated from without the furnace.

The stirring-arms F are secured to the shaft to rotate `with it, andthere is provided, preferably, a pair of stirring-arms for each of thehearthsE E', secured to the shaft diametrically opposite each other. Themeans for securing the arms to the shaft and for cooling both the shaftand the arms will now be described.

The shaft D is internally provided with longitudinally-extending inletand outlet passages for the circulation of a cooling fluid, preferablyair, being for this purpose preferably provided with longitudinalpartitions 12, separated from each other to form a central inlet-passage12 and an outlet-passage 12b on each side of the passage 12, the passage12 opening at the lower end of the shaft to the interior of the hollowstandard 1, to which may be connected any suitable air or other suitablecooling fluid supply. The sides of the shaft at the points where it isdesired to secure the stirring-arms are perforated, the perforations foreach pair of arms being opposite each other and correspondingperforations being formed in the partitions 12. In these perforationsare secured fittings 13 for receiving the ends of the stirring-arms andwhich are formed to direct the cooling medium through the stirring-arms.These fittings 13 are preferably in the form of hollow cylindricalsleeves, as shown, which may be formed with circumferential bosses 14 toengage and secure a snug fit with the sides and partitions of the shaftwhen the sleeves are set in the shaft. To aid in setting the fittings inthe openings in the shaft and in removing them, they are preferably ofslightly-tapering form externally. When the surface of the fitting iscut away to leave the bosses 14 for engaging the walls and partitions ofthe shaft, the bosses determine the shape of the fitting so far as itsengagement with the shaft is concerned and are of such relative diameteras to secure the desired tapering form. Suitable means are provided forholding the fittings against turning in the shaft. W hen of cylindricalform, as shown, studs or screws 15 .air-passages, the upper of which isagain divided midway of its length by a partition 19. The lower passage18 has a port 20, which opens to the passage 12 of the shaft, and theupper passages 18b have ports 21, which open into the passages 12b ofthe shaft. The stirring-arms are hollow and have alongitudinallyextending partition 22, which forms within the arms anoutwardly-extending passage 22 and a return-passage 22b for the coolingfluid, said passages connecting at or near the outer end of the arm. Atthe inner ends of the arms the partitions 22 extend in position to abutagainst the partitions 18 of the fittings 13 when the arms are inposition. The passage 22 of each arm will thus be in communicationthrough the passage 18 of the fitting with the inlet-passage 12 of theshaft, and the return-passage 22b of each arm will bein communicationthrough a passage 18D with one of the passages 12b of the shaft. The airor other cooling fluid passing' upward through the shaft passage 12,part of it will pass through the port 2O of each of the several fittings13 and then flow in both directions outward through the passage 18 andthe passages 22 of the oppositely-extending arms and then back throughthe return-passages 22b of the arms to the passages 13b of the fittingand thence through the ports 21 to the outlet-passages 12" of the shaft.The cooling fluid will thus be caused to fiow through the length of boththe shaft and the stirring-arms, and these parts being thus cooleddeterioration will be reduced to a minimum. To secure a better coolingof the part of the arm which rests in the sockets formed in the ends ofthe fittings 13, that part of the arm is provided with a plurality ofgrooves 24 and perforations 25, as shown in Fig. 5. By the ernploymentof these grooves and perforations the air is allowed to circulatebetween the arms and the sockets, thereby cooling them and preventing toa large extent the deterioration of that part of the arm and of theprojecting ends of the fittings 13. Any suitable means may be providedfor securing the arms in the sockets. Preferably, however, and as shown,in order to enable the arms to be removed as rapidly as possible fromthe sockets the projecting ends 17 of the fittings are per- .forated andthere is a corresponding perforation in the end of the arm which entersthe socket, and the arms are held in place by pins 26, placed in suchperforations. The arms may thus be removed from the socket with IOO IlO

but a very short stopping' of the furnace, the operator having' simplyto open the apertures '27 (see 1) in the wall of the furnace, inserttongs or other similar instrument, pull ont the pin` and withdraw thearms. The employment of this simple means for securing' the arms permitsthe apertures in the fm'- nace to be reduced to minimum size, which isan important factor, because of course the larger the aperture thegreater is the amount of cold air necessary to belet into the furnaceduring the operation of removing' the arms. In order to obtain therequisite strength of the arms without unduly increasing' their weight,the arms are preferably formed, as shown, with a longitudinalvertically-extending swell or hollow rib Q8 on the upper side of thearm. Such form of arm is especially desirable when the arms are securedto the shaft as shown and described herein and g'ives the necessarystrength and rigidity to the arms without requiring' the use of boltsextending' through the arms and without necessitating' undesirableincrease of weig'ht.

ln cases where it may not be desirable or necessary to cool the arms fortheir entire length. but only to cool the shaft, the fitting's 13, andthe connecting' ends of the arms, a construction such as is shown inFig. T may be adopted. In this construction the hollow sleeve-fittings13 are employed, having' the annular bosses 1l and the projecting'soclieted ends 1T extending through the sides of the shaft; but as thecooling' fluid is to flow only through the shaft and not through thearms the partitions in the shaft and in the arms and the ports andpartitions in the fittings 13 are omitted and the air or other coolingfluid fiows directly through the shaft,passing' around the fittings 15.With this construction the arms are preferably provided with shoulders29 to abut against the ends of the fittings 13 and limit the insertionof the end of the arm into the socket.

By the employment of the fittings lwhich are preferably held in place inthe shaft merely by being tightly fitted and without any positive means,the sleeve when deteriorated or when not properly fitting' owing' todeterioration of the shaft may be readily withdrawn from the shaft bytong's passed through the apertures in the furnace-wall and anothersleeve having' bosses l-.t of the proper dimensions inserted. By theemployment of such fitting's,therefore,constructed as describeththenecessity of cooling down the furnace and withdrawing the shaft for thepurpose of inserting' a new shaft is largely obviated, thus avoiding' aserious difficulty heretofore encountered in the operation of this typeof furnaces.

No claim' is made in lthis application to the combination in aroasting-furnace of a series of' superimposed hearths having' concentricopenings, a rotatable hollow shaft extending' through said openings anddivided internally by a longitudinal partition joined at its edges tothe wall of the shaft to form inlet and outlet passages for a cooling'fluid extending' long'itudinally of the shaft, and stirring-arms carriedby the shaft and having a longitudinal outwardly-extending passageconnecting' with the inlet-passag'e of the shaft and a returnpassageconnecting' with the outlet-passag'e of the shaft.

'hat is claimed is- 1. In a roasting-furnace. the combination of aseries of superimposed hearths having concentric openings, a rotatableshaft extending' through said openings, detachable fittings carried byand extending' bodily into the shaft, and stirring-arms detachablysupported by said fittings, substantially as described.v

2. In a roasting-furnace, the combination of a series of superimposedhearths having concentric openings, a rotatable shaft extending' throughsaid openings, detachable fittings carried by and extending bodily intothe shaft, and stirring-arms detachably supported by said fittings, theshaft and the stirring-arms having connecting-passages for thecirculation of a cooling' fiuid longitudinally through the shaft and thesti wing-arms, substantially as described.

3. In a roasting-furnace, the combination with a series of superimposedhearths having concentric openings, a rotatable hollow shaft extendingthrough said openings, fittings detachably mounted in said shaft andextending transversely through the shaft with their ends extending'through openings in the wall of the shaft, and stirring-arms detachablysupported by said fittings, substantially as described.

1. In a roasting-furnace, the combination with a series of' superimposedhearths having concentric openings, a rotatable hollow shaft extendingthrough said openings, fittings detachably mounted in said shaft andextending transversely through the shaft with their ends extendingthrough openings in the wall of the shaft, and stirring-arms detachablysupported by said fitting', the shaft and the stirring-arms and thefittings having connecting-passag'es for the circulation of a cooling'`fluid longitudinally throug'h the shaft and thel stirringarms,substantially as described.

5. In a roasting-furnace, the combination of a rotatable hollow shaft, afitting' detachably mounted in said shaft and arranged transverselythereof and extending' bodily into the shaft through an opening' in thewall of the shaft, and a stirring-arm detachably support- IOO IIO

ed by said fitting', substantially as described.

6. In a roasting-furnace, the combination of a rotatable hollow shaft, afitting' detachably mounted in said shaft and extending' transverselythrough the shaft with its ends extending' through openings in the wallof the shaft, and stirring-arms detachably supported by said fitting',substantially as described.

7. In a roasting-furnace, the combination of a rotatable hollow shaft, afitting detachably mounted in said shaft and extending transverselythrough the shaft with its ends extending through openings in the wallof the shaft, and stirring-arms detachably supported by said fitting,the shaft and the stirringarms and the fitting havingconnecting-passages for the circulation of a cooling fluidlongitudinally through the shaft and the stirring-arms, substantially asdescribed.

8. In a roasting-furnace, the combination of a rotatable hollow shaft, afitting detachably mounted in said shaft and extending transverselythrough the shaft with its ends extending through openings in the wallof the shaft and having sockets formed Vin its ends, and stirring-armshaving ends formed to fit in the sockets in the ends of the fitting,substantially as described.

9. In a roasting-furnace, the combination of a rotatable hollow shaftdivided internally to form longitudinally-extending inlet and outletpassages for a cooling fiuid, fittings detachably mounted in said shaftand extending transversely through the shaft with their ends extendingthrough openings in the wall of the shaft, said fittings being' formedwith inletpassages and ports connecting with the inletpassage of theshaft, and outlet-passages cornmunicating with the outlet-passage of theshaft, and stirring-arms detachably supported by said fittings andhaving longitudinal outwardly-extending passages connecting with theinlet-passages of the fittings and returnpassages connecting with theoutlet-passages of the fittings, substantially as described.

10. A fitting for roasting-furnaces for connecting stirring-arms with ahollow rotating shaft, said fitting being formed of a sleeve adapted toextend transversely through the shaft and having its ends formed toconnect with and support the ends of the stirring-arms, and havingannular bosses to fit openings in the walls of the shaft, substantiallyas described. v

11. A fitting for roasting-furnaces for connecting stirring-arms with ahollow rotating shaft, said fitting being formed to extend through theshaft and having its ends formed to connect with and support the ends ofthe stirring-arms, substantially as described.

12. A fitting for roasting-furnaces for connecting stirring-arms with ahollow rotating shaft, said fitting being formed of a hollow sleeveadapted to extend transversely through the shaft and divided internallyto form inlet and outlet passages to communicate with inlet and outletpassages of the stirring-arms and having ports for connecting its inletand outlet passages with inlet and outlet passages of the shaft,substantially as described.

13. A fitting for roasting-furnaces for connecting stirring-arms with ahollow rotating shaft, said fitting being formed of a hollow sleeveadapted to extend transversely through the shaft and divided internallyto form inlet and outlet passages to connect with the inlet and outletpassages of the stirring-arms, and havinginlet and outlet ports for saidpassages, substantially as described.

14. In a roasting-furnace, the combination of a rotatable shaft, asocket carried by said shaft, and a stirring-arm havingits end set insaid socket, the shaft and the stirring-arm having connecting-passagesfor the circulation of a cooling fluid, the end of the stirring-armsbeing formed with perforations 25 connecting with grooves 24 for thecirculation of the cooling fluid between the end of the stirring-arm andthe socket, substantially as described.

15. In a roasting-furnace, the combination of a rotating shaft, and ahollow stirring-arm carried by said shaft havinga horizontally-arrangedpartition and having a hollow vertically-extending longitudinalstrengtheningrib 28, substantially as described.

16. In a roasting-furnace, the combination of a rotatable hollow shaft,a tapering fitting detachably mounted in said shaft and extendingtransversely through the shaft with the ends extending through openingsin the shaftwalls, and stirring-arms detachably supported by saidfitting, substantially as described.

17. In a roasting-furnace, the combination of a rotatable hollow shaft,a detachable fitting carried by and extending bodily into the shaft, astirring-arm detachably supported by said fitting, and means for causingthe circulation of a cooling fluid through the shaft, substantially asdescribed.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

FREDERIC J.'FALDING. Witnesses:

J. A. GRAVES, A. L. KENT.

